Fucoidan coatings for vascular stents
Cardiovascular diseases often require the use of permanent metal stents to maintain blood flow. These stents currently remain in place for the life of the patient. They cannot be degraded, and may lead to chronic stimulation of the vascular wall, endothelial dysfunction, inflammation, and the formation of scar tissue under the stent which may narrow the blood vessel once again.
The long term complications of permanent stents may be overcome with the biodegradable alternatives. Biodegradable magnesium alloy stents can be degraded and absorbed once the supporting role of restoring blood flow is complete. Still in their infancy, these magnesium alloy stents present challenges in terms of rapid degradation, poor haemocompatibility and the ineffective regulation of vascular cells. A functional surface coating is an exciting potential method that may overcome these challenges.
A recent study developed a fucoidan-based coating for a biodegradable magnesium alloy stent and explored its effects on corrosion resistance and biocompatibility in comparison to an uncoated stent. In vitro studies demonstrated that the fucoidan-based coating exhibited both improved corrosion resistance and haemocompatibility. Furthermore, the endothelial cells and smooth muscle cells exhibited distinct dose-dependent behaviours towards the fucoidan grafting density. The relatively low fucoidan grafting density promoted the proliferation, spreading and migration of endothelial cells, but suppressed these behaviours in smooth muscle cells.
Further exploration involving implantation of the stents in an animal model indicated that the fucoidan-based coating inhibited thickening of arterial walls, relieved tissue inflammation and promoted rapid endothelialisation.
Researchers concluded that the fucoidan-based coating provided ‘a simple and effective strategy to develop novel magnesium alloy stents with improved corrosion resistance, good haemocompatibility and pro-endothelialisation potential.’ Researchers also suggested fucoidan-based coatings may be useful in the development of other blood-contacting implants.
The full paper, ‘Fucoidan-based coating on magnesium alloy improves the haemocompatibility and pro-endothelialisation potential for vascular stent application’, was published in Materials & Design.